Preheat the oven to 400°F.
Toss the fingerling potatoes with olive oil, salt, and pepper. Arrange in a baking dish, cover, and roast for 20–25 minutes.
Nova Scotia sea salt, 1 lb fingerling potatoes, 4 tbsp olive oil, freshly ground black pepper
Uncover the potatoes, stir, and continue roasting for 20 minutes, or until tender and lightly golden.
To make the caper butter, melt the butter in a small pan over medium heat. Add the onion, capers, and lemon juice. Simmer briefly and remove from heat.
1/2 cup butter, 1/4 cup capers, 1/2 medium red onion, juice of half a lemon